1. Field of the Invention
The present invention relates to a process for producing an extremely hard, non-brittle, strongly-adhering mixed carbide layer on ferrous materials to improve their specific properties such as wear resistance and corrosion resistance.
2. Description of the Prior Art
Processes for producing wear-resistant surface layers on ferrous materials by means of thermo-chemical methods are already known. According to U.S. Pat. No. 2,685,545 (Sindeband), it has been proposed to coat ferrous materials having a carbon content of at least 0.4% with a metal carbide layer having a Vickers hardness of ca. 1500 to 1600. According to this known proposal, the carbide layers can also be in the form of a mixed carbide layer containing at least 2 metals from the group consisting of chromium, vanadium, titanium, columbium, tantalum, molybdenum and tungsten. The ferrous workpiece is packed in a casehardening powder containing at least two of the aforementioned metals. The piece then undergoes a heat treatment in the 500.degree.-1700.degree. C range. This is designed to produce a mixed carbide layer having a hardness of 1500 VH.